The present invention relates to an apparatus and a method for drawing heat from a first heat reservoir and a second heat reservoir and transferring heat to a first heat sink and a second heat sink using a working fluid.
Adsorption heat exchange systems, in particular adsorption refrigeration systems, often use solid adsorbent beds to adsorb and desorb an adsorbate depending on the temperature. A basic adsorption refrigeration system can contain four main components: a solid adsorbent bed, a condenser, an expansion valve and an evaporator. The solid adsorbent bed may desorb a refrigerant when heated and adsorb it when cooled. In this manner, the bed may be regarded as a thermal compressor. The refrigerant vapor is cooled and condensed to liquid in the condenser. The refrigerant condensate then expands to a lower pressure through an expansion device. The low pressure condensate vaporizes in an evaporator by drawing heat from a process medium or a medium to be cooled. When further heating no longer produces desorbed refrigerant from the adsorbent bed, the bed is isolated and allowed to return to the adsorption conditions. When the adsorption conditions are established in the bed, the refrigerant vapor from the evaporator is reintroduced to the bed to complete the cycle.
To ensure a continuous and stable operation, two or more adsorbent beds are used. A cycle time refers to a time for the completion of a full cycle of adsorption and desorption. The heating and cooling steps are reversed when the beds reach the desired upper and lower temperature limits. A cooling efficiency or coefficient of performance (COP) can be described by the ratio of a cooling effect to an energy input. A compactness of the system is reflected by specific cooling power (SCP), which is defined as the ratio of the cooling energy to the cycle time and adsorbent weight.